(a) Field of the Invention
The present invention relates to a power control method and resource management method of a femtocell base station in a wideband wireless access system. Particularly, the present invention relates to a power control method and resource management method of a femtocell base station in a wideband wireless access system with mixed macrocells and femtocells.
(b) Description of the Related Art
Recently, the femtocell is actively studied in order to allow high-speed wireless data communication in the home or offices. Very small base stations targeting the femtocell are provided at a cheap price and are operable by the plug-and-play system.
The methods for managing the femtocell are the closed network system and the open network system. The closed network system allows the authenticated terminal to access the corresponding closed network. Therefore, the closed network system does not provide good handover, and it is required to solve the problem of interference with terminals belonging to another closed network or another open network within the coverage of the corresponding closed network.
Particularly, in order to guarantee communication of the terminals belonging to the macrocell in the femtocell, transmitted power of the femtocell base station is determined in the prior art as expressed in Equation 1.Pfemto (dB)=min(Pmacro-rx+L(d)+G, Pfemto-max)   (Equation 1)
Here, Pmacro-rx is received power of a macrocell base station received by the femtocell base station, L(d) is a path loss caused by femtocell coverage, and Pfemto-max is the maximum power strength transmittable by the femtocell. Also, G is a power control limit.
In Equation 1, as the femtocell base station is provided nearer the center of the macrocell, it uses greater transmitted power, and as it is provided nearer the macrocell edge, it uses lesser transmitted power. The reason of using the above-noted method is to reduce the interference applied by the femtocell base station toward the terminal belonging to the macrocell, the terminal being located on the corresponding macrocell edge. However, when the method is used, the problem of seriously deteriorating the downlink yield of the femtocell may occur.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.